One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,4,8,6,3,5,7)(9,10)(11,19,22,15)(12,23,26,16)(13,18)(14,17)(20,30)(21,35,27,31)(24,32)(25,36,28,33)(29,34)(37,38)(39,40)(1,3)(2,6)(4,7)(5,8)(9,11)(10,15)(12,24)(13,27)(14,22)(16,32)(17,19)(18,35)(20,25)(21,29)(23,40)(26,39)(28,38)(30,33)(31,34)(36,37) involution — undirected(2,7)(3,8)(4,5)(9,12)(10,16)(11,20)(13,28)(14,26)(15,30)(17,23)(18,36)(19,37)(21,39)(22,38)(24,27)(25,29)(31,40)(32,35)(33,34) involution — undirectedA Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.